I'm enjoying this thread. I'm in the same boat so perhaps my perspective will add some value: I have a basically stock 2015 Trail w/ KDSS and have had analysis paralysis on lift/tire choices.
My goal: CONFIDENT and COMFORTABLE "light expedition" style travel through the Rocky Mountains (think Alpine Loop in Colorado, similar trails in Wyoming, and Montana); NOT rock hopping, boulder crawling, or mud-running. And of course, it has to satisfy daily-driving duties to the office and daycare.
I would like a little more ground clearance and really want to run the 255/80/17 Cooper ST Maxx's. I have been torn between an 'economical' set of 5100's vs. a full on adjustable coil over lift like the Toytec Boss. I am right now leaning towards the Toytec Boss lift
BOSS Suspension System for 10+ 4Runner and FJ
...and for the following reasons:
1) Good reputation for overall product quality and ride quality. I've talked to a few members on here specifically about this kit.
2) Not as expensive as say an ICON setup
3) Infinite and independent adjustability up front to accommodate potential hardware additions/changes such as winches, dual batteries, compressors, and of course any 'lean' issues due to the lift, etc.
4) At the end of the day, it's about $600 more than the $400 5100 setup with some $200 rear coils. $600 is still a lot of dough but having the future flexibility of the suspension to change and grow as the mods do has value. I'd hate to spend $600 on a 5100/rear coil setup and then a year or two down the road need to change something, add more lift, tweak things here and there, and have to buy more parts to accomplish that (making what I've already bought obsolete). This is kind of that "buy once, cry once" philosophy". The Toytec lift can be set at 0" and grow up to 3" (personally, I don't think I'll ever go over 2").
Anyways...that's my mindset right now.
(In addition to the lift, I'll be adding sliders and skids - likely BudBuilt - to help with the confidence and durability on the trail)